This present invention concerns an impact detection device, as well as a system that includes such a device. It is employed particularly in electronic training systems for a combat sport, or for simulation of such a combat sport, and in boxing, karate, kendo, or fencing in particular. More generally, the invention is employed in electronic training systems for a sport in which the user creates an impact by striking an adversary or a support, directly or by means of an object that is liable to transmit the impact.
Such systems necessitate the use of impact detection devices that are designed to detect an impact on a support as a result of a strike or a blow by the user onto this support.
In general, these impact detection devices are in fact used to detect the impact, and to record it in order possibly to display a result or a score on a screen.
However, such devices cannot be used to indicate, directly at the impact site, that the impact has indeed occurred. Moreover, they cannot be used to guide the user before impact, that is to indicate to the user where he should strike.
One is also aware, from document WO 2004/070336, of a punchbag for training in a combat sport, that includes an impact detection device.
This device includes a sensor of the piezoelectric type, designed to detect the strike, and an indicating element, of the digital display device type, associated with the sensor, the whole being mounted on a support that is attached to the punchbag.
The strike or the impact on the sensor is detected by this sensor, which transmits a detection signal directly to the indicating element, that is then activated (display of a value on the display device).
One of the drawbacks of such a device is that the indicating means are not located at the impact site. It is therefore not possible, with such a device, to design a use during which one indicates to the user the location at which he should apply the impact by activating the indicating means.
We are also aware, from document U.S. Pat. No. 4,974,833, of a system for the practice of a combat sport that includes a control unit connected to an impact detection device located at an impact site.
The impact detection device includes a sensor that is designed to detect an impact, and indicating means associated with the sensor.
The control unit is designed to receive a signal on the part of the impact detection device, indicating a strike in the area concerned, and possibly the force of this strike.
This control unit is also designed to emit a signal that is intended for the impact detection device, which activates the indicating means associated with the sensor, with the aim of indicating to the user that he should strike at a given location.
More precisely, the system includes an impact detection device. This impact detection device includes a sensor located at an impact site and designed to detect an impact in this zone, as well as indicating means.
The sensor is a vibrating cone of the loudspeaker type. It is mounted on a printed circuit board, in a cavity that is closed but perforated with holes for transmission of the vibrations.
The indicating means are LEDs, which are placed flush with the surface of the impact detection device, and preferably coated with silicone. A layer of the elastic synthetic foam type is placed around the LED. This layer is also placed between the LEDs and the surface, and between the cavity and the sensor.
Again we are aware, from document WO 2005/049154, of a target that includes an impact detection device mounted on a substrate, with a support for absorbing the energy of the device on the substrate.
This device includes a first sensor of the piezoelectric type on the target, and a second sensor of the piezoelectric type on the substrate.
Expressed otherwise, in this document, the sensor is mounted on one face of a plastic target disk, on the other face of which a printed circuit is mounted. Indicating means, in the form of diodes, are mounted in a circle on this printed circuit.
The face of the printed circuit on which the diodes are mounted, that is on the side opposite to the sensor, is covered with a sort of transparent dome.
However, neither in document U.S. Pat. No. 4,974,833 nor in document WO 2005/049154 is there any direct impact on the sensor.
In fact, in U.S. Pat. No. 4,974,833, a layer for transmission of the vibrations is also used to activate the sensor.
Furthermore, in WO 2005/049154, the pressure on the rigid support disk is communicated to the sensor only if this pressure is sufficient to crush the elastomer ring until it causes the sensor to press onto a second rigid support disk.
As a consequence, the detection of an impact is not sufficiently efficient and sensitive.
Finally, we are aware, from document U.S. Pat. No. 3,580,575, of a device in which a sensor and diodes are mounted in a circuit, with the whole being embedded in a protective resin, so that the diodes are located close to the surface of this embedding material.
This type of device cannot be used to obtain good accuracy in terms of information regarding the location of the impact, since the diffusion of the light emitted by the diodes within the embedding material does not allow one to see the impact with any accuracy. This is particularly important in the case where the device is employed in a network that includes a large number of such devices, some of which can be located close to each other.
The purpose of the invention is therefore to offer a solution to the aforementioned problems, amongst others.
The invention therefore refers, according to a first aspect, to an impact detection device, intended in particular to be used in an electronic training system for a combat sport.
This device includes at least one sensor, preferably of the piezoelectric type, designed in particular to detect an impact, and the intensity of this impact, and which is mounted on a printed circuit.
The device also includes indicating means that are designed to be activated when the sensor detects an impact and/to indicate to a user that he should initiate an impact. These indicating means include at least one means for the emission of a light signal, of the electroluminescent diode type for example, and embedded in a protective embedding material and located close to the surface of this embedding material.
The indicating means are mounted directly on the printed circuit, with the embedding material also enclosing the printed circuit and the sensor.
Characteristically, the device also includes a channel for transmission to the sensor of the light signal emitted by the means for the emission of a light signal.
Thus, with the sensor and the indicating means placed at the same level on the printed circuit, and protected by the embedding material, it is possible to position this device so that it will directly receive the impact, and so that this impact will therefore be detected with precision and efficiency by the sensor.
In addition, the indicating means accurately indicate the impact site, with no danger of being damaged or causing injury to the user.
In a first variant, the indicating means include at least one first indicating means designed to be activated when the sensor detects an impact, and at least one second indicating means, separate from the first indicating means, and designed to be activated so as to tell a user that he should initiate an impact.
In a second variant, possibly in combination with the preceding one, the channel includes a tunnel, which can be in a plastic material such as opaque silicone. The means for the emission of a light signal is then placed at the entrance to or inside the tunnel, and the sensor is placed close to the exit from the tunnel.
In a second variant, possibly in combination with any one or more of the previous ones, the indicating means can include a large number of means for the emission of a light signal, preferably of the electroluminescent diode type, possibly distributed in a circle around the sensor, for example.
In yet another variant, possibly in combination with any one or more of the previous variants, the device includes means for the transmission and reception of a signal.
These means for the transmission and reception of a signal can be designed to emit a signal when the sensor detects an impact, with the emitted signal preferably being a function of the intensity of the impact, and to receive a signal for activation of the indicating means.
The embedding material can be composed of a material, of the silicone type for example, with a diffraction index such that the light signal, emitted by the means for the emission of a light signal, is diffused so as to be visible from the outside of the device.
In another variant, possibly in combination with any one or more of the previous ones, the embedding material also constitutes the outer envelope of the device.
In yet another variant, possibly in combination with any one or more of the previous ones, the embedding material is of more-or-less cylindrical form.
The invention also refers, according to a second aspect, to a system, in particular for the practice of a combat sport or training for a combat sport, such as boxing.
This system includes a main body that is intended to receive impacts on the part of a user.
Characteristically, the main body includes at least one impact detection device such as presented above.
In a first variant, the system includes a control unit.
This control unit includes means for the transmission and reception of a signal, and is designed to emit a signal that is intended for the impact detection device in order to activate the indicating means, and to receive a signal on the part of the impact detection device when an impact is detected by the latter.
The indicating means should preferably include means for the emission of a light signal of variable colour and/or of variable intensity, with the control unit being designed to activate the means for the emission of a light signal of a given colour and/or with a given intensity according to a given training sequence and/or a given action to be executed by the user.
In a second variant, possibly in combination with the preceding one, the main body constitutes a punchbag, for the practice of boxing for example.
This punchbag includes an outer envelope at least partially filled with padding.
The main body preferably includes an inner envelope, placed between the outer envelope and the padding, and the impact detection device is placed between these outer and inner envelopes.
Alternatively, the main body constituted a garment or one part of a garment, such as a garment for the practice of fencing for example.
The main body can also constitute an accessory to be worn on the body, such as a helmet, a glove or a shoe, or one part of this accessory.